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That old/tired subject: hub-centric and lug-centric

8K views 11 replies 8 participants last post by  TxFireman1972 
#1 ·
I was hoping to put some KMC XD Monsters on my 06 350. They have a bore of 125.5 mm, whereas the hub is 125.22. There's no way to fit a hub-centric ring in there (would a piece of steel .005" even make a difference?) so I'm just forced to rely on the studs for bearing weight? That scares me.

If they can machine them to within .28mm, why wouldn't they go the extra bit and make them hub centric?

I really miss Weld.
 
#3 ·
Why woudl that scare you? You are not relying on the lugs shafts to hold the weight of the truck. Its not shear force threshold. The lugs provide clamping force and it and the friction is what holds the truck up. Look up the clamping force of what one of those studs and bolt @ the spec 165ftlb TQ applies then all 8 lugs. It is way over the capacity of not only the wheel tire but of the axle
 
#4 ·
Been done that way for a long time. My wheels are lug centric now as well as the last set was.All my aftermarket wheels have been lug centric.If you don't know how to install them properly then have someone show you and you will be fine.
 
#7 ·
That actually is not true. If you actually did have the weight on the lugs and not the compression friction clamp force you would likely break lugs but also wallow out the alum wheel lug holes. You are looking at static load and not shock load. Imagine what the force is on say a rear tire in a max loaded 350 when it hits a pot hole or other harsh road irregularity. I do not have the formula for the math but you would be surprised at the type of shock loads that can be created. Fact is that neither the lugs nor the center hub ring were ever meant to support the vehicle. The hug centeric just allows for easier equal torquing of the lugs nuts. As it centers the wheel nut tightening patterns and steps are not as critical although why not do it right. I figure factories has to worry about he lowest common denominator of stupidity of owners and being sued by them. That is why you get hub-centeric from OEM and rarely from aftermarket and of course cost. A factory can have 1 mil wheels made all to spec. A aftermarket would like to use a wheel for as many different vehicles as possible.
 
#8 ·
part right the "shock load" is greatly decreased by the side wall of the tire and you wheel studs are held in a single shear. Now at the same time if your nuts were lose you would have taken away the shear and are left with a twisting and pulling not a strait shear. any time you have 2 flat object bolted riveted together you create a shear point. and also all factory rims are hubsentric
 
#9 ·
Oh sure get all technical about it. LOL
 
#10 ·
Very few aftermarket wheels are available hub-centric. I would say 95% (maybe more) of aftermarket wheels being used are lug-centric. I guarantee you'll have someone post on this thread that you should NEVER run a lug-centric wheel. There are always a few out there that believe it and swear by it. Maybe in a perfect world, everything would be hub-centric, but the truth is, most people running aftermarket wheels are not running hub-centric ones. A big factor is the fact that there are not many companies that offer them because they are way too vehicle specific, and like the poster above said, they prefer one wheel to fit many vehicles. So to find a hub-centric wheel usually gets pretty pricey.
 
#11 ·
Usually the wheel maker bores the hole to the largest application and you put hub rings in the wheel to fit your application. Every wheel I own is hub centric (6 different brands on 4 vehicles), the hub rings are like $11 a piece. All my racing wheels are required by regulation to be hub centric, doesn't have anything to do with load bearing, but concentricity. No, I'm not going to spew out that everyone should buy hub centric wheels or else you'll die crap, I do it to minimize NVH and damper issues, or in the case of the center-lock wheels, because it's required.
 
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